Microloop avoidance in SR-MPLS networks
During topology changes, the network undergoes a process of flooding link state information across its nodes. Each router independently employs the shortest path algorithm to construct its own representation of the topology. However, this decentralized approach may introduce microloops in the network as the convergence of internal gateway protocols might not be synchronized among all routers.
To address this issue, SR-MPLS networks implement microloop avoidance configurations, as outlined in the IETF proposal, draft-bashandy-rtgwg-segment-routing-uloop. In cases where a source router lacks confidence in the loop-free nature of the post-convergence path to a destination, it can establish an explicit path without generating any state along that route. This explicit path is maintained briefly, providing sufficient time for the network to converge. Subsequently, the post-convergence path is installed in the RIB, FIB, and LFIB.
The stage is...